It is known that Claviceps fungus strains are able to biosynthesize ergot alkaloids on rye in a host-parasite inter-relationship. About the clavine-producing Claviceps strains it was also known that they produce the alkaloids in question also under saprophytic conditions [M. Abe et al.: J. Agric. Chem. Soc. (Japan) 25, 458 (1952)]. While the latter way was not used for plant-scale manufacture, it provided an adequate basis for the research of the biosynthesis of the skeleton [L. C. Vining: Can. J. Microbiol. 12, 915 (1966) and H. G. Floss: Tetrahedron 32, 873 (1976)].
The first process used in industry was worked out by G. T. Banks et al. [J. Gen. Microbiol. 82, 345 (1974)]. In this process a Claviceps fusiformis strain was isolated from Pennisetum typhoideum sclerotium and then improved by repeated selection to obtain a higher yielding strain. The new strain produced agroclavine.
Then Z. Rehacek et al. prepared new mutants of the strain Claviceps purpurea. One mutant produced primarily agroclavine, while two other ones produced primarily elymoclavine. However, in the case of both elymoclavine-producing mutants the alkaloid level was only 300-600 .mu.g/ml in the fermentation broth [J. Nat. Prod. 44, 225 (1981)].
The Soviet patent specification No. 735,010 as well as Prikl. Biok. Microbiol. 16, 569 (1980) disclose a native strain of Claviceps fusiformis producing six different alkaloids with a total alkaloid level of 1220 .mu.g/ml, in which the elymoclavine portion amounts to 70-75%.
S. H. Ambiket et al. [Phytochem. 9, 1953-58 (1970)] have found that clavine-producing strains of the Claviceps purpurea type contain cytochrome P-450, and the level of the latter can be increased with phenobarbitone, resulting in a simultaneous increase of the alkaloid level produced by the strain.